1. Field of the Invention
The invention of the present application relates to a cushion made of elastomer and a bed using the same.
The invention of the present application relates to a bed cushion made of elastomer and a bed using the same, and more particularly to a cushion with thin diaphragms arranged in a lattice.
The invention of the present application relates to a cushion made of elastomer that is used for a bed for preventing bedsore, a normal bed, a chair, a sofa, or the like and exhibits a satisfactory property.
The invention of the present application relates to a mold for forming a cushion used for a bed for preventing bedsore, a normal bed, a chair, a sofa, or the like.
2. Description of the Related Art
Bed cushions are required to have comfortableness during sleep as well as a function of supporting and holding a weight of a human. Specifically, the cushions are required to have appropriate softness, compressibility, high vibration absorption, deformation compliance, and no flattening. In the past, cotton, web of synthetic short fiber, synthetic resin foam such as polyurethane, coil springs, or the like has been used alone or in combination.
Attention is also directed to shapes of bed cushions, and a known bed cushion has, for example, an uneven surface, or thin and vertical diaphragms arranged in a lattice. A known bed cushion with thin and vertical diaphragms arranged in a lattice, for example, has the diaphragms made of sponge rubber, semirigid materials, or gel materials (Japanese Utility Model Laid-Open No. 52-15307, U.S. Pat. No. 5,749,111 specification). The diaphragm made of sponge rubber provides cushioning by compression of the sponge rubber of the diaphragm, which is likely to cause, so called, a feeling of touching a bottom.
The cushion with the diaphragms made of semirigid materials provides cushioning by tilting the diaphragms toward a side, and thus there are disadvantages of lacking softness when a user lies thereon and inferiority in soft absorption of light load. Especially, there is hardness in bounce which the user feels when the user's body touches the diaphragms forming the cushion to start to be compressed.
The diaphragm made of gel materials provides cushioning by bending the gel materials of the diaphragm and has good cushioning, but has a problem of lacking durability such as early occurrence of, so called, flattening because it is the gel material.
As described above, for forming the cushion with thin and vertical diaphragms arranged in a lattice on plan view, a molds is required that configures gaps (cavities) for forming thin diaphragms in a lattice on plan view when the mold is fitted.
A mold N100a for forming the above described cushion has diaphragms Nb formed in a lattice on plan view by forming protrusions N102 in substantially square prisms arranged vertically and horizontally in a protruding manner from a substrate N101, and filling resin such as semirigid materials in gaps (cavities) N102a formed between the protrusions N102 to thereby (FIG. 27).
As a mold for forming a similar cushion, there is a mold N100b constituted by a lower mold N100b1 and an upper mold N100b2 as shown in FIG. 28.
The lower mold N100b1 has a predetermined number of protrusions N103 formed into substantially square prisms and provided in a standing manner and insertion spaces N104 to be formed in the protrusions N103, alternately arranged in one plane formed by a substrate N109.
The upper mold N100b2 has protrusions N105 in substantially square prisms to be inserted in the respective insertion spaces N104 of the lower mold N100b1 with gaps N107 to be cavities for forming diaphragms Nb of the cushion left, and insertion spaces N106 in which the respective protrusions N103 of the lower mold N100bl are inserted to form the gaps N107 to be cavities, alternately arranged in one plane formed by a substrate N100. Then, the lower molds N100b1 and upper N100b2 are fitted, and, with peripheries thereof surrounded by a frame mold N100c, resin such as semirigid materials is filled into the gaps N107 formed between the molds N100b, N100b2 to form the diaphragms Nb.
As described above, when forming the cushion with the diaphragms in a lattice on plan view using soft resin materials such as semirigid materials by the lower molds N100a, upper molds N100b, a product can be relatively easily removed from the molds after forming the cushion because of high removability of the product.
This cushion is a cushion having a structure where thin and vertical diaphragms are arranged in a lattice on plan view as described above, and causes no feeling of touching a bottom in use and can maintain high absorption for a long time by forming the diaphragms using elastomer such as thermoplastic elastomer or rubber.
This cushion is formed by the mold using elastomer having a relatively sticky surface such as styrene based thermoplastic elastomer, or polyolefin based thermoplastic elastomer. Therefore, when a product is removed from the mold after forming, the sticky surface of the product sometimes attaches cavity surfaces or corners in the cavity of the mold (blocking). In this case, there are problems that removal from the mold takes time to prevent smooth removal operation of the product, and that a stripping trace caused by forceful removal remains on a surface of the cushion subjected to serious blocking.
The object is to provide a mold from which a product can be easily and neatly removed by effectively reducing stick or blocking caused when removing the cushion that is formed using sticky elastomer in forming as described above from the mold.
The cushion PD has high absorption. However, when load is applied by contact with the user, the diaphragms formed in a lattice are appropriately bent and buckled to thereby achieve absorption, so that openings of the lattice that receives the user's body are sometimes blocked by the body of the user PA (FIG. 29).
This often happens when the user rolls over, and air in the lattice blocked by a weight of the user is compressed and jetted from a gap generated between the opening and the user's body, sometimes hissing. This noise is relatively small, but may annoy a sick user. Further, the cushion configured as described above provides satisfactory cushioning, but compared with a cushion containing liquid or gel materials such as a water bed, a feeling of touch which a user feels when touching it is different, and a soft feeling of touch like the water bed cannot be achieved.
Further, four diaphragms are concentrated to form a cross at a crossing portion of the respective diaphragms arranged in a lattice. This compromises flexibility at a center of each crossing portion of the cushion and generates bounce like partial protrusions, and sometimes gives an uncomfortable feeling to a user when he lies on a contact surface of the cushion.
This cushion is a cushion having a structure where thin and vertical diaphragms are arranged in a lattice on plan view as described above, and causes no feeling of touching a bottom in use and can maintain high absorption for a long time by forming the diaphragms using elastomer such as thermoplastic elastomer or rubber.
The above described cushion has high absorption, but when the diaphragms having received load are buckled to thereby achieve absorption, and thus, compared with a cushion containing liquid or gel materials such as a water bed, an initial feeling of touch which a user feels when he lies thereon is different, and a soft feeling of touch like the water bed cannot be achieved.